Field of Invention
The present invention relates to an inorganic film, and more particularly to a low density, ultrathin, and environmentally friendly film and its preparation method, wherein the low density, ultrathin, and environmental film can be used for crop cultivation and for making shopping bags or trash bags.
Description of Related Arts
With the advancement of agricultural technology, the film technology using mulch films is widely used in the cultivation of crops, such as cotton, corns, and vegetables, wherein the application of this technology has greatly increased the crop yields and reduced the plant growth cycle thereof. As a result, the demand of the plastic film is gradually increased also. In addition, an enormous amount of plastic film are used for manufacturing shopping bags and trash bags for daily use. Generally speaking, the plastic bags are made of polyethylene (PE) film because of its higher strength. However, the PE film cannot be reused and is not degradable, such that the PE film will cause lots of pollution, such as “white pollution”. An improved plastic bag is made of biodegradable films as the replacement of the PE film for solving the pollution problem. In order to ensure the film to be biodegradable, a predetermined amount of corn starch is added into the PE film to upgrade the PE film as the biodegradable film. However, molds are easy to grow in the corn starch and are less attraction for bacteria or other living organisms. The biodegradable rate of this plastic film is low.
In order to solve the technological problems of the biodegradable films, the film manufacturers use Rich Mineral Paper (RMP) or stone paper, which as a paper-like product, as a substitution of the corn starch to make the biodegradable film. In particular, a predetermined amount of calcium carbonate is added into the PE film to make this biodegradable film. However, this biodegradable film has several drawbacks. The thickness of this biodegradable film is about 0.08-3 mm. In other words, the biodegradable film is relatively thick and heavy comparing with the conventional PE film. In other words, this biodegradable film cannot be made as the ultrathin film. It is worth mentioning that the thickness of the film for the shopping bags or trash bags is about 0.006-0.02 mm. Therefore, this biodegradable film cannot be used as for making the shopping bags or trash bags.
Accordingly, a low cost, light weight, ultrathin, and highly degradable agricultural film is provided to satisfy the market needs and solve the industry's problems.